package com.itheima.web.servlet;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class code extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
public code() {
	super();
}

/**
	 * Destruction of the servlet. <br>
	 */
public void destroy() {
	super.destroy(); // Just puts "destroy" string in log
	// Put your code here
}

/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

	response.setContentType("text/html");
	// 使用java图形界面技术绘制一张图片

				int charNum = 4;
				int width = 30 * 4;
				int height = 30;

				// 1. 创建一张内存图片
				BufferedImage bufferedImage = new BufferedImage(width, height,
						BufferedImage.TYPE_INT_RGB);

				// 2.获得绘图对象
				Graphics graphics = bufferedImage.getGraphics();

				// 3、绘制背景颜色
				graphics.setColor(Color.YELLOW);
				graphics.fillRect(0, 0, width, height);

				// 4、绘制图片边框
				graphics.setColor(Color.BLUE);
				graphics.drawRect(0, 0, width - 1, height - 1);

				// 5、输出验证码内容
				graphics.setColor(Color.RED);
				graphics.setFont(new Font("宋体", Font.BOLD, 20));

				// 随机输出4个字符
				Graphics2D graphics2d = (Graphics2D) graphics;
				 String s = "ABCDEFGHGKLMNPQRSTUVWXYZ23456789";
				Random random = new Random();
				//session中要用到
				String codemsg="";
				int x = 5;
				for (int i = 0; i < 4; i++) {
					int index = random.nextInt(32);
					String content = String.valueOf(s.charAt(index));
					codemsg+=content;
					double theta = random.nextInt(45) * Math.PI / 180;
					//让字体扭曲
		            graphics2d.rotate(theta, x, 18);
					graphics2d.drawString(content, x, 18);
					graphics2d.rotate(-theta, x, 18);
					x += 30;
				}

				// 6、绘制干扰线
				graphics.setColor(Color.GRAY);
				for (int i = 0; i < 5; i++) {
					int x1 = random.nextInt(width);
					int x2 = random.nextInt(width);

					int y1 = random.nextInt(height);
					int y2 = random.nextInt(height);
					graphics.drawLine(x1, y1, x2, y2);
				}

				// 释放资源
				graphics.dispose();

				// 图片输出 ImageIO
				ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
				
				//验证码加入session域中
				request.getSession().setAttribute("currentcode", codemsg);
			
}

/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

	response.setContentType("text/html");
	PrintWriter out = response.getWriter();
	out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
	out.println("<HTML>");
	out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
	out.println("  <BODY>");
	out.print("    This is ");
	out.print(this.getClass());
	out.println(", using the POST method");
	out.println("  </BODY>");
	out.println("</HTML>");
	out.flush();
	out.close();
}

/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
public void init() throws ServletException {
	// Put your code here
}

}
